Table schema for binary storage  Chapter 30: Configuring Custom Java Class Lists

Chapter 29: Configuring Persistence Mechanisms

Requirements for in-memory stateful failover

You can use in-memory storage to support failover for stateful components by choosing CtsComponents/HeapStorage as the storage component. This feature allows component state to be maintained on a pair of servers, without incurring the overhead of using a remote database to store component state.

The in-memory failover implementation is based on mirror pairs. A mirror pair consists of two servers that are members of a cluster. The servers use the EAServer message service to synchronize component session state held in memory. If one server in a mirror pair goes offline, the other remains to serve client sessions for the mirrored components. You can configure multiple mirror pairs within a cluster, but each server can be a member of only one mirror pair.

NoteIn-memory failover requires the following:

Cluster configuration for in-memory failover

Chapter 6, “Clusters and Synchronization,” in the EAServer System Administration Guide describes how to configure a cluster. To support in-memory failover, you must define mirror pairs within the cluster.

A mirror pair consists of two servers within the cluster that use the EAServer message service to replicate state information for session components hosted on those servers. Servers in a mirror pair should have the same set of stateful components installed. One server cannot be a member of more than one mirror pair.

StepsConfiguring mirror pairs

  1. Display the Mirror Groups tab in the Cluster Properties dialog box.

  2. Click Add.

  3. Enter the IIOP URLs for the two servers in the mirror pair, separated by a comma. For example:

  4. Repeat to add as many mirror pairs as required.

StepsConfiguring server session cache size

  1. For each logical server in a mirror pair, configure the server property This property specifies the maximum size of the memory cache used to hold session data for components running on the server. The value has the same syntax as the Cache Size property described in “Mirror Cache tab component properties”.

Mirror Cache tab component properties

On the Mirror Cache tab, configure the following:

Copyright © 2005. Sybase Inc. All rights reserved. Chapter 30: Configuring Custom Java Class Lists